300 VERTEBRATA. AVES. 



same direction as the thumb. This conformation 

 enables some of the genera to climb the perpen- 

 dicular trunks of trees, which has given a name to 

 the order, derived from partial grounds ; for whereas, 

 as we have seen, some of the Tenuirostres climb in 

 great perfection, some of the Scansores do not climb 

 at all, as the Trogons and Cuckoos. They feed 

 for the most part on fruits, or insects, according 

 to the firmness of the bill ; some appear even to 

 prey on small vertebrate animals. They are forest 

 birds, usually building their nests in hollow trees. 

 Generally speaking, they are birds of considerable 

 size, and adorned with brilliant and, in some in- 

 stances, metallic colours. 



Picus,* the Woodpecker. 



No birds are better qualified to display " the 

 wisdom of God in the works of creation," than these. 

 Every part of their structure (and it is rather a 

 singular one) points to a single instinct, and is ad- 

 mirably adapted for it. The food of the Wood- 

 peckers consists almost exclusively of insects, which 

 dwell safe from all other assailants in the solid wood 

 of trees. To obtain these, many contrivances are 

 necessary, many deviations from the form of other 

 birds. The large and strong toes arranged in pairs 

 give them great power of maintaining their footing 

 on a perpendicular surface, and the body is addi- 

 tionally supported by the stiff and horny tail, com- 

 posed of strong feathers ending in sharp points, 



* Its ancient Latin name. 



